Bug 2497410 - CVE-2026-9547 curl: curl: Man-in-the-middle attack via SSH host key bypass [fedora-all]
Summary: CVE-2026-9547 curl: curl: Man-in-the-middle attack via SSH host key bypass [f...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: curl
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Jan Macku
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["ee76bccd-42cc-40c3-991b-b...
Depends On:
Blocks: CVE-2026-9547
TreeView+ depends on / blocked
 
Reported: 2026-07-06 17:59 UTC by Jon Moroney
Modified: 2026-08-07 01:37 UTC (History)
7 users (show)

Fixed In Version: curl-8.18.0-8.fc44 curl-8.15.0-8.fc43
Clone Of:
Environment:
Last Closed: 2026-08-07 01:37:12 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Jon Moroney 2026-07-06 17:59:50 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

When a libcurl-based application performs transfers via `SCP://` or `SFTP://`
and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an
untrusted server. This vulnerability occurs when a server presents a host key
type that does not match the specific key type already recorded for that host
in the `known_hosts` file. Instead of rejecting the mismatch, the callback
mechanism fails to properly enforce the restriction, allowing the connection
to succeed without warning and risking a potential man-in-the-middle attack.

Comment 1 Fedora Update System 2026-07-31 12:02:43 UTC
FEDORA-2026-e691fbbfe7 (curl-8.18.0-8.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-e691fbbfe7

Comment 2 Fedora Update System 2026-08-01 15:55:50 UTC
FEDORA-2026-e691fbbfe7 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-e691fbbfe7`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-e691fbbfe7

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 3 Fedora Update System 2026-08-02 00:56:25 UTC
FEDORA-2026-e691fbbfe7 (curl-8.18.0-8.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 4 Fedora Update System 2026-08-04 08:42:07 UTC
FEDORA-2026-097fb2e7e9 (curl-8.15.0-8.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-097fb2e7e9

Comment 5 Fedora Update System 2026-08-05 01:32:51 UTC
FEDORA-2026-097fb2e7e9 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-097fb2e7e9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-097fb2e7e9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-08-07 01:37:12 UTC
FEDORA-2026-097fb2e7e9 (curl-8.15.0-8.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.


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